This invention relates to a multi-line telephone switching system, and more particularly to a system for routing multi-line telephone inputs to output devices, such as answering machines, facsimile machines, modems, or the like, on a line-by-line basis.
Throughout the following description, the term "answering machine" will be used to describe the answering device to which the present invention is connected, it being clear that the term "answering machine" is being used generically and includes within its scope any other type of answering device, such as facsimile machines, modems, computers, telephone answering machines, data receiving devices or any other device which answers telephone lines automatically.
When a plurality of telephone lines are to be coupled to a single (or plural) answering machine, a problem exists if the answering machine or the like is busy with another call. In such case, if a call comes in on a second line, the answering machine cannot interrupt its connection to the first call, and the second call continues to ring. Sometimes, the caller on the second line will merely hang up if the phone is not answered. In manually operated switchboards, this problem is overcome by the operator putting the first call on hold, then switching over to the second call to answer same, informing the second caller to "please wait" or the like, and then going back to the first call for continuing the attention to the first call. In automatic answering devices, however, this cannot be done, and the second incoming call is ignored until the answering machine is free.
The object of the present invention is to provide a switching system which can be connected to an automatic answering device, and which answers and manages calls coming in on additional lines, even when a first line is busy and is connected to the answering device.